The invention refers to a cooling system for cooling of electric components or circuits with at least one cooler possessing a housing through which a coolant can flow and at least one first cooling surface that can be splashed with the coolant as well as at least one second cooling surface for flange mounting or fastening of at least one electric component or circuit.
A very wide variety of cooling facilities or systems are known for cooling of electric components and/or circuits, for example systems that use natural air convection, or for higher capacities, systems in which cooling occurs by means of an air stream produced by a ventilator or fan.
For very high capacities, cooling systems are also known that have a cooler through which a liquid coolant flows (EP 0 611 235). Although these watercooled cooling systems enable a high cooling capacity, they have the disadvantage, among other things, that the coolant must be recooled, that corrosion or sealing problems occur, as well as problems caused by the electrical conductivity of the coolant. Moreover, with these water-cooled cooling systems it is necessary that the cooler and the heat exchanger for recooling are compatible.
The object of the invention is to provide for a cooling system that avoids these disadvantages of the prior art.
For this purpose a cooling system for cooling of electric components or circuits or modules is provided with at least one cooler possessing a housing through which a coolant can flow and comprises at least one first cooling surface that can be splashed with the coolant as well as at least one second cooling surface for mounting or fastening of at least one electric component or circuit. The coolant is compressed air and/or a gas under pressure. Means are provided for injecting water in the form of fine droplets or a fine spray into the coolant, wherein the effective size or surface area of the first cooling surface is at least 2.5 times as great as the effective surface of the second cooling surface.
In a preferred embodiment the coolant into which the water is injected has a relative humidity of less than 90 percent, i.e. before the injection of the water.
It has been shown that by injecting water droplets into the air or gas stream used as a coolant, a high cooling capacity can be achieved despite the use of this coolant (air or gas stream), among other things, precisely due to the fact that especially the thermal resistance of the transfer between cooler and coolant is reduced significantly, indeed as much as 50 percent in comparison with cooling purely be means of a gas stream and/or air stream.
The invention has the additional advantage that at the same cooling capacity only a notably reduced quantity of gaseous coolant (cool air and/or cool gas) is necessary. Whereas for example a flow rate of at least 30-40 m/sec is necessary for cooling purely with air or gas, the flow rate can be reduced to 5 m/sec at a cooling system according to the present invention with a cooler of the same size and the same dissipating capacity.